From verso of card: "Great care must be taken to see that the respirator is correctly fitted and adjusted, in order that a supply of pure air, quite free from gas, is ensured for breathing. The respirator is made so that it fits closely around the face, and is provided with adjustable straps to hold it in the correct position. It is important that the respirator be tried on and the straps properly adjusted to the requirements of the wearer . . . so that it may be put on at a moment's notice."